Street and highway paver



Nov. 16, 1965 E. s. KUBALA 3,217,621

STREET AND HIGHWAY PAVER Filed Dec. 29, 1960 5 Sheets-Sheet 1 VVE/v70@Eli ha $.Kubala mgl wm wmm mm@ vm v n .nw Qn S mm Nov. 16, 1965 E. s.KUBALA STREET AND HIGHWAY PAVER 5 Sheets-Sheet 2 Filed DSC. 29, 1960 Elsha 5. Kuba/a ATTORNEY NOV- 15, 1955 E. s. KUBALA 3,217,621

STREET AND HIGHWAY PAVER Filed Dec. 29, 1960 5 Sheets-Sheet 3 Elisha S.Kuba/a by da @W ATTORNEY Nov. 16, 1965 E. s. KUBALA 3,217,621

STREET AND HIGHWAY PAVER Filed Deo. 29, 1960 5 Sheets-Sheet 4 Fig. Il

Elisha S. Kuba/a ATTORNEY Nov. 16, 1965 E. s. KUBALA STREET AND HIGHWAYPAVER 5 Sheets-Sheet 5 Filed Deo. 29. 1960 E /isha S. Kuba/a ATTORNEYUnited States Patent O 3,217,621 STREET AND HIGHWAY IAVER Elisha S.Kubala, 1439 NE. 29th St. Oklahoma City, Okla. Filed Dec. 29, 1960, Ser.No. 79,413 7 Claims. (Cl. 94-48) My invention relates to improvements invibrated pan-type surfacing apparatus.

INTRODUCTION The general concept of vibrating freshly laid concrete,before it begins to set, is well known. As applied to the laying ofconcrete pavement, this technique produces the beneficial results ofdewatering and densifying the concrete before it hardens, resultingultimately in a stronger pavement.

Two well known species of apparatus for surfacing concrete With the aidof vibration are the vibratory screed, in which the concrete levelingaction of the machine is largely dependent upon a transverselyreciprocating strike-off member having auxiliary vibrators attached toit, and the vibrating pan, in which the leveling action is producedprincipally by hard, downward, high frequency vibratory impulsestransmitted to the surface of the concrete by a tamping member havinglittle or no transverse movement. The mode of operation found invibrating pan apparatus is believed more compatible with the productionof strong pavement than that of the vibratory screed. Nevertheless, thelatter type of apparatus appears to have enjoyed considerably widercommercial acceptance, despite many efforts in the past to produce anacceptable vibrated pan type of machine. Because the vibrated pan typemachine relies primarily on vibration instead of transversereciprocation of its concrete contacting means, the intensity ofvibration required in such a machine is of necessity considerably morepotent than that normally produced in the vibratory screed machines inwhich the vibration is only an accessory of their mode of operation.

In practice, the required intensity of vibration for a successful pantype machine has led to a number of problems, among which are theproblems of metal fatigue and undue shaking of the supporting frame,i.e. carriage, of the machine. This may well explain the poorer thanexpected acceptance of such machines. Accordingly, despite the manyprior attempts at producing an acceptable vibrated pan type machine,there remains a demand for improvements therein which alleviate orlessen the above described problems.

OBI ECTS It is a principal object of this invention to fulfill the abovedescribed demand. Another object of this invention is to provide avibratory paving machine adaptable not only for shaking paving material,but also for subjecting it at the same time to a vigorous tampingaction.

It is also an object of this invention to provide improved means forconnection of the concrete-contacting member of a paving machine withthe carriage thereof whereby the transmission of vibrations through saidconnection is minimized.

Another object of this invention is to provide a vibrated pan-typepaving machine which is comparatively light in weight, inexpensive toconstruct, highly resistant to failure due to crystallization of vitalparts and capable of compacting concrete to a very high density atrelatively high speed.

THE INVENTION BROADLY I have found that the above objects, and otherobjects which will readily become apparent to one skilled in the j3,217,621 Patented Nov. 16, 1965 art from the drawings and thefollowing: description, are fuliilled by a paving machine having: acarriage and propulsion means therefor; a pan; rotary vibrationproducing means mounted upon said pan and adapted to rotate about anaxis generally perpendicular to the line of travel of the machine; and avibration filtering system associated with said pan and said carriage,said vibration filtering system comprising a multiplicity fof filterunits, each of said filter units comprising spring means, a first membersecured to said spring means, a second member supportively associatedwith said first member in `a manner allowing substantially horizontalreciprocatory motion of said second member with respect to said firstmember parallel to the line of travel of the machine, and means forsecuring said lter unit to said pan and said carriage.

My invention will become better understood by reading the description ofit which follows in conjunction with the accompanying drawings in whichlike numerals refer to like parts throughout the several figures and inwhich sectional views are taken in the direction of the reference arrowson the ends of each section line. In the drawings:

FIGURE 1 is a back elevation of the machine in place upon curb forms.

FIGURE 2 is similar to FIGURE l except that in FIG- URE 2 the pan israised clear of the pavement.

FIGURE 3 is a section through the pan and main beam of the machine.

FIGURE 4 is a section through the wheel extension shafts showing the panraising apparatus.

FIGURE 5 is a top view of the pan raising apparatus of FIGURE 4.

FIGURE 6 is a detail view of the wheel drive assembly taken from outsidethe end of the machine..

FIGURE 7 is a perspective view of a broken out portion of the machinetaken from the back and looking towards one end of the machine from apoint near its center.

FIGURE 8 is a detail of the eccentric rotor shown in FIGURE 7.

FIGURE 9 is a sectional view of the rotor of FIGURE 8, showing a brokenout portion of the main beam and depicting the mode of vibration of thepan.

FIGURE 10 is a perspective detail View taken from the front of themachine loo-king towards the wheels. The seat assembly, control stationand control rods have been omitted from this view for the sake ofclarity.

FIGURE ll is a schematic diagram of the hydraulic power distributionsystem for operation of the machine.

FIGURE l2 is a top view of the machine in place upon curb forms, withthe motors, pumps and. control rods removed for the sake of clarity.Similar omissions are made in FIGURES 13 through 15.

FIGURE 13 is a front elevation of the machine finishing a dat slab.

FIGURE 14 is a front elevation of the machine with the wheels adjustedto ride upon curb forms while finishing a crowned street.

FIGURE l5 shows a front elevation of the machine finishing one halfwidth of a crowned street with one set of wheels adjusted to ride uponthe curb, the other upon a form level with the crown of the street atits center.

FIGURE 16 is a perspective view showing the sleeve and stub shaftrelationship of a vibration lilter unit.

It should be understood that the above-mentioned drawings and thedescription which follow are given by way of illustration, notlimitation, and represent only what is presently considered by theinventor to be a preferred embodiment of his invention. It is obviousand should be readily apparent to those skilled in the art thatmodifications and changes can be made without departing from the spiritof this invention. Therefore it is intended that all such changes shallbe included within the purview of the claims appended hereto.

THE CARRIAGE The carriage is a rolling support for the machine andderives its support from the forms (FIGURES 1 and 2) containing a bodyof concrete 21, shown here with preformed curbs. The heart of thecarriage assembly is the main beam 23, which runs across the greaterpart of the Width of the machine. Upon the main beam are located wheelassemblies and means for raising and lowering them; a control station;the power plant and power distribution system; thrust absorbers; andhangers for the vibration filtering means which support all or part ofthe weight of the pan, depending upon whether the machine is inoperation or not.

The main beam 23 of the machine is an I beam having a hump or a crown atits center. Thus, the main beam has a higher elevation at the center ofthe machine than at the sides thereof.

Stationed at approximately equidistant points across the top of mainbeam 23 are hangers 39 (see FIGURE 3), supported by posts 40, weldeddirectly to the top of the beam. The hangers aid in supporting the panin a manner to be explained below and carry guide blocks 4l on theirupper surfaces for steadying control rods 38. Located at various pointsalong main beam 23 between said hangers are a reservoir 143 and a numberof bases 42 for a gasoline engine 141 and various hydraulic motors andvalves which are controlled by the control rods 38. These motors andvalves are part of the power distribution system which will also beexplained later. The control rods all terminate in handles at a controlstation 29 on one side of the carriage.

The carriage is constructed in such a manner that the gauge andelevation of its wheel assemblies 33 may be varied. Adjustments havebeen provided to give several different ranges of wheel height relativeto the beam (and the pan). The machine has been provided with the meansto continuously vary the wheel height within said ranges and may, withinlimits, be adjusted to any width of pavement, as well. One or more ofthe above functions is carried out by the stanchions 24, fulcrum plates30, pivotable arms 25, extensible shafts 26 and lift cylinders 28, whichwill now be described in detail as to their placement and manner ofcooperation.

The upright stanchions 24 are Welded directly to the ends of the mainbeam. Several feet inboard of said stanchions on the main beam arelocated fulcrum plates 30, which depend from cross-beams 31 weldeddirectly to beam 23 (see FIGURE 10). Each fulcrum plate on the machineis provided with three holes 45, 46 and 47, which correspond to threedifferent fulcrum points around which the pivotable arms 25 may becaused to swing. Said arms are secured by nuts 48 and bolts 49 which mayeasily be removed for the purpose of changing the fulcrum point.

In order to steady the arms 25, they have been connected by across-brace 50 and have been provided with buffers 51 (see FIGURES 4 and5). The inner faces of the arms 25 freely slide up and down over thevertical faces of the buffers, which prevent the arms 25 and theircross-brace 50 from twisting the fulcrum plates 30 as the carriage movesbackwards and forwards.

The outer ends of the pivotable arms 25 have box sections 32 whichslidably receive extensible shafts 26 and hold said shafts in place bymeans of set screws 52. The shafts 26 are secured to wheel assemblies oneach side of the machine.

As shown in FIGURES 4 and 5, the stanchions 24 are fabricated of angleiron stock 53, leaving a space which is partially closed in by smallerangles 54, resulting in a track which accommodates a slide 55. To theslide 55 is connected one end of lift cylinder 28, the other end 4 ofsaid cylinder being connected to cross-brace 50. In order to preventdamage to the cylinder and x a uniform limit of downward travel for bothsides of the machine, each slide 55 is provided with stops 73 welded tothe front of said slides. Said stops are positioned in such a mannerthat they halt further downward travel of the beam, when the cylinder isalmost fully retracted, by contacting the top surface of cross-beam 50.

The upward thrust of cylinder 28, exerted through the slide 55, is borneby a long adjusting screw 56 threaded into a cap 57 welded to the headof stanchion 24 and said screw being held safe against unintended changeof position by a lock-nut 58. The bottom of said screw abuts the head ofthe bracket 59 by which cylinder 28 is pivotably secured to the slide55.

Changes in the gauge of the machine are made by loosening the setscrews52 and sliding the extensible shafts 26 on each side of the machine inor out until the desired gauge is obtained. Then the set-screws 52 areIetightened.

Each of the holes 45, 46 and 47 in fulcrum plates 30 corresponds tothree ranges of wheel height, high, medium and low, respectively. Forwork on flat slabs without curbs, the low range (holes 47) would beused. For work on streets with low or high curbs, medium or high range(holes 46 or 45 respectively) would be employed. By means of the longadjusting screws 56, the fulcrum point of the retracted lift cylinders28 may be adjusted up or down to level the Wheels after the fulcrumpoint of the arms 25 has been shifted. Then, once the range has beenset, as outlined above, the lift cylinders 28 may be extended by feedinghydraulic fluid under pressure to them, thus lifting the beam (and thepan) to any height within the limits of extensibility of the cylinders.Not only are the height ranges of the left and right sides of themachine adjustable independently of one another, but also the same istrue of the lift cylinders, as will be shown during the description ofthe power distribuation system.

Directing the attention now once again to` the wheel assemblies shown inFIGURES 1 and 2, it will be observed that atop the assembly 33 on thesame end of the machine las the control station 29 is a box frame 34,auxiliary seat mount 35 and seat 36. Said seat may be mounted eitherupon the box frame or the auxiliary mount, and the auxiliary mount mayitself be mounted outboard of the frame 34 as shown in FIGURES l and 2or inboard of said frame (not shown). The purpose of the multi-positionseat assembly is to make it possible to locate an operator sitting uponsaid seat at a convenient distance from the fixed control station 29, nomatter how little or how far the wheel assemblies 33 are extended fromthe carriage.

All of the wheels on the machine are driving wheels. However, the leftWheel assembly and right wheel assembly both have their own individualdriving motor which makes it possible to drive one set of wheels fasterthan the other, or even to completely stop one set of wheels while theother set continues to drive its side of t're machine forward orbackwards. This innovation makes it possible for the machine tonegotiate short radius turns.

A hydraulic motor 61 (see FIGURE l0) located on a motor post 60, weldedto the frame of each wheel assembly 33 turns the wheels of each assembly(see FIG- URE 6) through a reducer 64, drive chain 63, and sprockets 65,located on the wheels 66. The wheels rotate on shafts 67 journaled inbearings 68 allixed to the side frames 69 of each wheel assembly 33.

THE PAN Partially surrounding the main beam across its entire length isthe pan, which has a high front face '70, a wide bottom (concretecontacting) face 71 and a low rear face 72 (see cross section in FIGURE3). As may be observed in FIGURES l, 2, 7, l0 and 12-15, the pan isdivided -into six individual sections 81-86, each of said sections beingpivotally linked to its neighbor by front splice plates 91-95 and rearsplice plates 1111-105. Each splice plate is welded to one of twoadjacent pan sections and held fast to the other section by nuts andbolts. For instance, in FIGURE the splice plate 91, which joins togetherpan sections 81 and 82, is welded to the front face of pan section 81and secured by bolts to the front face of section 82. The bolts securingthe front and rear splice plates may be loosened for the purpose ofadapting the pan for forming a contour, such as a crown in the pavementbeing laid. The bolt holes in the pan which are hidden behind the spliceplates are enlarged to permit the movement necessary for suchadaptation.

Near each side of the pan, the front face of the terminal pan section iscut back to prevent interference between the pan and the buffers 51which have been purposely projected forward of the front of the pan inorder to keep the pivotable arms 25 from striking the pan when said armsare in their lowest position. This is best illustrated in FIGURE 10 inwhich the arrow numbered 75 indicates the place to which the front faceof pan section 81 has been cut back. In order to guard against theoverilow of concrete into the pan across the top of this cntawayportion, flexible skirt 74 having a cut-out 76 for the buffer 51 to passthrough is secured to the pan in place of the cut-away portion of itsfront face.

By adding extensions (not shown) it is possible to increase the overallspan or length of the pan. Such extensions may be fabricated of sheetsteel in the form of open-top boxes which should have the same depth andwidth as the ends of pan sections 81 and 86. The extensions, which canbe made in several lengths, may be detachably bolted to the ends of theouter pan sections so that the bottom, front and rear faces of theextensions are flush with fthe bottom front and rear faces of the pansections to which they are attached.

As an aid to proper distribution of the poured concrete in preparationfor the first contact of thepan therewith, the inventor prefers toprovide the pan with an auxiliary leveling device rigidly secured inspaced apart relation to the front face of the pan. In this embodimentof the invention (see FIGURES 3, 10 and 12-15) said leveling deviceconsists of a plurality of plates 112415 (shown best in FIGURE 12) whichare about the same length as the pan sections 82-85 respectively, towhich said plates are joined by rigid Spacer bars 122-126. To the endsof the plates 112 and 115 nearest the wheel assemblies 33 are attachedplates 111 and 116, which are somewhat shorter in span than the plates112 through 115, but are similarly supported by rigid spacer bars 121and 127 respectively. Deilectors or wings 110 and 117 are provided atfthe outer extremities of plates 111 and 116 respectively, said wingsbeing also supported by side braces 120 and 12S respectively.

Proportionally longer spacer bars are used for each successive plate inprogression from spacer bar 124, which is at the center of theyauxiliary leveler between plates 113 and 114, to the outermost spacerbars 121 and 127. Therefore the outermost plates extend further forwardthan the inner or middle plates and the outer ends of the deflectors,which are at an even greater angle with the pan front than said plates(as seen in FIGURE 12), extend further forward than any other part ofsaid leveling device.

The manner of fastening the aforesaid plates to the spacer bars is suchthat the contour of the lower edges of the plates may always be set toapproximate the contour of the pan, no matter whether the pan is set fora flat or crowned pavement. This is accomplished by overlapping adjacentplates at that spacer bar which is common to each and securing saidoverlapping plates to their common spacer bar by a means of fasteningwhich may be loosened to allow pivotal motion of said plates about anaxis perpendicular thereto. For instance, as

shown in FIGURE 10, adjacent plates 111 and 112 overlap at spacer bar122 and are aixed thereto by a machine screw 118 threaded into the frontof the brace 122. Each of the plates 111-116 -is joined in a like mannerto its neighboring plates and spacer braces.

The aforesaid machine screws, which pass through oblong verticallyoriented slots in the end of each plate, such as slot 119 in plate 111,are set tightly while the machine is in operating condition. Foradjustment of the contour created by the plates, the machine screws areloosened at the same .time the bolts on the pan section splice platesare loosened. As the angle of each pan section with the horizontal ischanged, a like change ris created in the angle of the plate in front ofit, since.

each pan section controls the position of the spacer bar attached to it`and said spacer bar controls the position of the plate in front of theindividual pan section. Since the position of each plate is governed bythe position of the pan section in front of which said plate is mountedthe contour of the auxiliary leveling device is controlled by the pancontour. When the adjustment of the pan and auxiliary leveling devicehas been completed, the machine screws may be retightened. The oblongslots allow the elevation of the plates to be varied with respect to thebottom surface 71 of the pan. The inventor prefers to have the bottom ofeach plate parallel to but elevated slightly above the bottom of thecorresponding pan section. Said elevation generally falls within therange of 1A inch to 3A inch depending upon the slump ratio of theconcrete being laid.

Mounted upon the back of the panare facilities for attaching thereto thenecessary vibrators and vibration filtering system. The facilities forattaching the vibration lters to the back of the pan include standardsISU-136. In this embodiment of my invention the standards take the formof short lengths of angle iron welded to the inside surfaces of the backand the bottom of the pan. Standards 131-135 are adjacent the rearsplice plates 101-105 and are attached to pan sections 81-85respectively. Standards and 136 are attached to pan sections 81 and 86respectively in close proximity to the ends of the main beam 23.

As shown in FIGURES 7 through 9, the vibrator mounts 129 are secured tothe pan by welding them to the inside surface of the back of the pan andto the inside surface of the bottom of the pan. A stifener 137 isemployed to impart rigidity to the pan in the vicinity of the vibrator.Said stitfener is welded to the mounts 129 and to the inside surface ofthe bottom of the pan and runs parallel to the back `of the pan.

THE VIBRATION PRODUCING MEANS` The vibrators must operate in a mannersuch that the pan motion produced thereby is a combination of circularor elliptical motion in a vertical plane and transverse waves resultingin vibratory up and down motion across the width of the pan. Variousmethods of providing the requisite Vibration are known and many feasiblemeans might be employed. Therefore, it is to be understood that it wouldnot be a departure from the spirit of my invention, nor from the scopeof the appended claims to substitute other means of producing thesimultaneous orbiting and vibration described above.

A simple and effective means of producing the needed vibrations is shownin FIGURES 7 through 9. Inside a tubular casing 77 attached to mounts129 is eccentric rotor 78 with shafts 79 and weight 80 journaled inbearings 88 so as to rotate about an axis perpendicuar to the line oftravel of the machine. One of the shafts carries a pulley 89. Theinventor has determined that rotors having eccentrics 1%. inches indiameter and 14 inches long, placed 1A inch off center and rotated at3000 to 5000 r.p.m. will give adequate vibration in a machine with a 28foot pan. The resulting pan motion has a vertical corn- 7 ponent of 3/16inch and a horizontal component of 1A inch.

Two vibrators are employed in the preferred embodiment of my invention.However, additional vibrators may be utilized if desired. When two areused, the effective center of each should be stationed halfway betweenthe center of the pan and one of its two ends (see FIG- URES 1 and 2).This manner of locating the vibrators aids in the establishment ofdesirable transverse vibrations. It is possible to interconnect therotors in order to keep them out of phase; however, practical experiencehas shown such interconnection to be unnecessary in the now preferredembodiment of this invention. The normal variations in speed and torquebetween the independent vibrator driving motors 90 and the occasionalslippage of the drive belts 140 which transmit power from the motors 90to the vibrator drive pulleys 89 insure that the vibrators will remainout of phase a sufficient proportion of the time for most work.

THE PROPULSION SYSTEM Any suitable mode of propulsion may be utilized,but the inventor prefers to drive this machine by means of a gasolineengine which turns a hydraulic pump for supplying hydraulic fluid underpressure to a fluid distribution system and hydraulic motors connectedthereto. The gas engine 44 is mounted on top of the main beam 23 nearthe center, as shown in FIGURES l and 2. The hydraulic pump 142 ismonuted on the main beam between the gas engine 44 and an oil reservoir43 for hydraulic fluid. The pump 142, as shown more fully in FIGURE l1,is provided with a relief valve 144, which is ported to the reservoir143 through a reservoir return line 145. An oil filter 147 may beinserted at any desired point in the system, such as between thereservoir and pump, to collect any foreign material which manages tofind its way into the system.

For distribution of the pressurized hydraulic fluid discharged from thecontinuously operating pump there is a pressure manifold pipe 146. Themanifold, as well as the reservoir return line 145 are secured andsheltered within the overhang of the main I beam 23 as shown in FIGURES3 and 7. At various points along the manifold and return lines, whichrun almost the entire distance across the span of the main beam 23, areports at which fluid under pressure is distributed to the wheel drivemotors' 61, vibrator drive motors 90 and lift cylinders 28 and portsthrough which spent fluid from said motors and cylinders is returned tothe reservoir.

The vibrator motors 90 are variable speed motors. Each motor has its owncut-off valve 148, 149 and throttle valve 150, 151 for Varying the rateof flow of hydraulic fluid through the motor, thus providing a means ofvarying its speed. Since each motor has its own throttle valve its speedmay be individually regulated.

Each of the lift cylinders 28 is provided with a Y valve 153, 154 bymeans of which fluid under pressure may be admitted to the cylinders toraise the pan or by means of which any amount of fluid in the cylindermay be ported to the reservoir. There is also a neutral position inwhich all of the ports of said valve are closed, permitting no fiuid toenter or leave said cylinder. Since each cylinder is provided with itsown independent valve,

the height of each cylinder may be varied and held ind L! 148, 149, theY valves 153, 154 and the reversing valves 155, 156 on bases 42 neartheir respective motors, and to utilize the control rods 38 to actuatethem. The throttle valves 150, 151, 157 and 158 are all mounted upon thecontrol station, where the operator may adjust them conveniently fromtime to time when necessary.

THE VIBRATION FILTERING SYSTEM Without an effective means of filteringvibrations developed in the pan, the vibrations would he transmitted tothe carriage of the machine and tear it apart by shearing off bolts,loosening nuts and crystallizing vital structural members. The inventorhas developed a filtering system which is simple, effective andtrouble-free. It has proven its ability over months of testing to almostentirely eliminate damage to the machine carriage due to vibrationtransmission.

The system comprises a multiplicity of identical filter units 160-166,170-176 located at the front and rear of the pan adjacent the jointsbetween pan sections and near the ends of the beam 23 (see FIGURES l, 2and l2-15). Each of the above-mentioned units comprises a sleeve 180, astub shaft 181, a long 4bolt 182, lock nuts 183, lower spring 184, upperspring 185 and bolt head 186. The rear units 1619-166 are afiixed bywelding or other suitable means of fastening to standards 13G-136 whichhave been provided therefor. The front filter units 171- 175 are weldedto the front pan section splice plates 91-95 respectively, the remainingfront filter units 178 and 176 being welded directly to the front facesof pan sections 81 and 86 respectively. All the sleeves 180 arepositioned on the pan so that their axes are at right angles to the axesof the vibrator rotors, which are parallel to the front of the pan. Thepositions of all the sleeves in the units 160-166 and 170-176 areexemplified by the positioning shown in FIGURES 3, 7 and l0 of thesleeves 188 in filter units 162, 172, 164, 170 and 171.

We now turn to a description of unit 164 in FIGURE 7, which isillustrative of all the other filter units in the machine save for themanner of attachment to the pan, in which unit 164 differs from thefront filters in the manner explained above. Within sleeve 180 is thestub shaft 181 which has a diameter such that it fits closely, but isable to move axially in said sleeve, parallel to the line of travel ofthe machine, with a minimum amount of friction. Through a diametric holeapproximately midway between the ends of stub shaft 181 is threaded thebolt 182. Oversize clearance holes 187 are provided in the sleeve 186for said bolt to pass through. The diameter of the aforementioned holesshould exceed the diameter of the bolt 182 by an amount which is atleast equal to the maximum horizontal component of the motion of the panunder operating conditions. (See FIGURE 16.) On the bolt, above thesleeve 180 are lock nuts 183, which constrain upwardly the lower spring184. Spring 184 is held in place on the bolt between said lock nuts andthe bottom of the hanger 39, through which the bolt 182 passes. Betweenthe upper surface of hanger 39 and the head 186 of the bolt is the upperspring 185.

The purpose of the upper springs is to yieldably support some or all ofthe Weight of the pan and to dissipate downward impulses which mightotherwise pass from the pan to the carriage. Therefore, the springs 185should be sufliciently powerful so that the full weight of the pan isnot great enough to fully compress them. To understand the importance ofthis requirement, it is necessary to note that a fully compressed springis inelastic to forces tending to compress it further and that anunyielding body will transmit vibratory impulses more readily than ayieldable body.

The purpose of the lower springs is to regulate the size of the verticalcomponent of the motion of the pan and to cushion upwardly directedimpulses which might otherwise rack the carriage. By loosening the locknuts and then tightening them upwards the tension on the lower 9 springsmay be increased. Increasing the tension of the lower springs increasestheir resistance to the upward movement of the pan and therefore has theeffect of diminishing the vertical component of the pan movements.

` The upper and lower springs cooperate to maintaln the pan at theproper height with respect to the carriage and forms while the machineis in motion. The lower springs aid, as explained in regulating thevertical component of the pan gyrations. The nature of the combinationof hangers, springs, bolt and lock nuts is such that there is nonon-resilient connection involved therein which is capable oftransmitting vertical vibratory impulses undiminished from the pan tothe carriage. i Horizontal fore and aft vibrations are dissipatedbetween' the` sleeve 180 and stub shaft 1&1. As the pan gyrates, it hasa horizontal component of motion which is shared by the sleeves 180,which are attached to the pan. However, since the stub shaft and sleeveare able to slide with respect to one another, the stub shaft and thecarriage tend towards a smaller component of horizontal motion than thepan. This is a result of the fact that no horizontal component of forcecan be transmitted t-o the stub shaft and carriage beyond the amount offorce required to move the sleeve back and forth over the stub shaft. Bysuitable means of alleviating friction between stub shaft 181 and sleeve180, such as 'by lubrication, it is possible to reduce the coefficientsof both the starting and sliding friction between these two parts to theextent that the transmission of horizontal fore and aft vibrations fromthe pan to the hangers by way of the vibration filters is minimized. V-Itis clear that certain changes might be made without departing from thescope of this invention. For instance, it would be possible to atiix thestub shafts 181 to the pan instead of securing the sleeves 180 to thepan. The bolts 182 would then be secured directly to the sleeves and notto the stub shafts. Clearly, the filter, although altered slightly,would still protect the carriage just as well without departing inprinciple from the mode of operation of the preferred embodimentdisclosed herein. It is equally obvious that many equivalents for thesprings 184 and 185 could be substituted therefor without departing fromthe spirit of this invention.

OPERATION OF THE MACHINE In the course of normal operation, concrete mixis piled in front of the preliminary leveling plates which strike `offthe concrete a fraction of an inch higher than the level of the pan. Asthe -machine proceeds forward, the level- Aing plates push a substantialbody of concrete ahead of them. The concave shape of the leveling deviceaids in keeping the excess concrete in front of the machine. In order toabsorb the thrust of the concrete `against the pan assembly, thrustsprings 189 and spring guides 19d are provided at intervals across thefront of the main beam Y23 (see FIGURE 3).

n l Since the preliminary leveling device is rigidly secured to the pan,it vibrates at the same frequency as the pan and densities the mixpartially while striking it olf. The lpreliminary leveling device isfollowed by the pan which simultaneously pounds and vibrates theconcrete beneath it. As the pan passes lover a given area of concretemix, the mix within said area is caused to vibrate en masse. Not onlydoes the pan transmit vertical impulses to the body of mix, but it alsotransmits positive horizontal impulses in two directions. The circularor elliptical motion of the pan sends out horizontal impulses parallelto the forms. The out-of-phase vibrator rotors also induce transversewaves which travel through the pan and are transmitted to the concretewherein said Waves travel perpendicular to the forms.

The resultant three-dimensional agitation of the mix is highly effectivein forcing the aggregates to migrate 4to the bottom and settle intointimate inter-locking contact with one another, while the lines areforced to the surface. The vibrations produced by this machine are hardenough to force a considerable amount of water out of the concrete alongwith entrapped air from deep within the mix. Densification of the mixand settling of the aggregates are performed so satisfactorily with themachine, that it has been found unnecessary to subsequently bull-floatthe concrete surface in most cases.

If it is necessary to make a second pass over the concrete surface toobtain the proper smoothness, this is easily accomplished. By valvingfluid to the lift cylinders 2S, the pan may be lifted clear of theconcrete (as shown in FIGURE 2). At the same time, the drive motorvalves and 156 should be reversed, causing the machine to back up to thepoint at which the second pass is to begin. The pan will then be loweredand the drive motors 61 will be started driving forward again.

The concentration of machine components and weight about a singletransverse beam as disclosed in this embodiment of the invention, makesit possible to build paving machines with a very short wheel-base. Thisis a distinct advantage, since it makes it possible for the machine tonegotiate short radius curves with ease. In order to improve thenegotiability of this machine still further, the inventor has conceivedthe idea of providing independent drives for the wheels on oppositesides of the machine. Thus on very short radius curves, the Wheels onthe inside of the curve may be slowed or stopped While the outer wheelscontinue to rotate at normal speed to traverse the longer arc of theoutside of the curve.

The new concept of paver construction embodied herein was conceived inan attempt to discover a Way of making a single paver do many differentkinds of work with only the simplest of modifications being requiredduring the transition from one type of work to another. The resultingmachine is capable of paving not only highways, as shown in FIGURES 13and 15, but also streets with curbs already in place, as shown inFIGURES 1, 2, 12 and 14. Not only may a full crowned street be laid asshown in FIGURE 14, but also very wide crowned streets may be laid intwo or more sections, as illustrated in FIGURE 15. FIGURE. 15 shows thewheels on one side of the machine riding upon curb forms, while theopposite wheels are running on a form which runs at pavement height downthe center of the road bed. Other kinds of work which may be performedby this machine will suggest themselves to those skilled in the art upona careful consideration of the above description and examples.

Having fully described a preferred embodiment of his invention, theinventor claims:

1. A paving machine having: a pan; vibration producing means mountedupon said pan; and a carriage with propulsion means therefor, saidcarriage being adapted to transporting and maintaining said pan at thecorrect Working level for finishing paving material being treated bysaid machine, said carriage comprising a horizontal main beam, verticalstanchions disposed upwardly from the ends of said main beam, adjustablefulcra secured to said main beam inboard of said stanchions, pivotablearms secured to said adjustable fulcra and extending outwardly therefromin a generally horizontal attitude, tracks formed in said stanchions, aslide confined within each of said tracks and adapted for verticaladjustment therein, means for adjusting and maintaining `the position ofsaid slide within said track, lifting means interposed and connectedbetween said. slide and said pivotable arms, receptacles in saidpivotable arms, telescoping shafts housed within said receptacles forvariable extension outwardly therefrom and wheel assemblies secured tosaid telescopic shafts, each of said wheel assemblies being providedwith individually controllable motor means.

2. A paving machine having: a carriage and propulsion means therefor;hanger means mounted on said carriage;

a pan; rotary vibration producing means mounted upon said pan andadapted to rotate about an axis generally perpendicular to the line oftravel of the machine; and a vibration filtering system connected withsaid pan and said carriage, said vibration filtering system comprising amultiplicity of identical filter units at spaced intervals across saidcarriage, each of said filter units comprising spring means, generallyvertically disposed means connected with said spring means and saidhanger means for generally vertical reciprocation, a first generallyhorizontal member secured to said generally vertically disposed means,and a second generally horizontal member connected in supportiveengagement with said first gennerally horizontal member for horizontalreciprocation with respect thereto and generally parallel to the line oftravel of the machine, said second generally horizontal member beingsecured to said pan.

3. A paving machine having: a carriage and propulsion means therefor,said carriage being provided with forwardly and rearwardly projectinghanger means at a plurality of spaced points across said carriage forseating spring means; a pan having a front and rear; rotary vibrationproducing means mounted upon said pan and adapted to rotate about anaxis generally perpendicular to the line of travel of the machine; and avibration filtering system connected with said pan and said carriage,said vibration filtering system comprising a multiplicity of pairs offilter units secured to said hanger means and to said pan, each of saidpairs of filter units comprising a pair of sleeves secured to said pan,one at the front and one at the rear thereof, said sleeves being in ahorizontal attitude with their axes parallel to the line of travel ofthe machine, each of said sleeves having a hole therein, said holehaving a dimension parallel to the direction of travel of the machinewhich is at least equal to the maximum horizontal vibration component ofthe pan under operating conditions, a reciprocable stub-shaft in eachsleeve, a member associated with each sleeve and being disposedreciprocably in a vertical attitude in said hanger means, the memberextending through the hole in said sleeve and being secured to saidstub-shaft, a first spring means, means for retaining said first springmeans on said member above said hanger means, a second spring means, andmeans for retaining said second spring means on said member below saidhanger means.

4. A paving machine having: a carriage and propulsion means therefor; apan; vibration producing means mounted upon said pan and adapted to setup vibrations in said pan having generally vertical and horizontalcomponents; a vibration filtering system connected with said pan andsaid carriage, said vibration filtering system comprising a multiplicityof filter units, each of said filter units comprising spring means,means connected with said spring means for generally verticalreciprocation, means supportively connected with said verticalreciprocation means for generally horizontal reciprocation with respectto said vertical reciprocation means, and means for securing said filterunits to said pan and said carriage; and said carriage comprising ahorizontal main beam, vertical stanchions disposed upwardly from theends of said main beam, adjustable fulcra secured to said main beaminboard of said stanchions, pivotable arms secured to said adjustablefulcra and extending outwardly therefrom in a generally horizontallyattitude, tracks formed in said stanchions, a slide confined Within eachof said tracks and adapted for vertical adjustment therein, means foradjusting and maintaining the position of said slide within said track,lifting means interposed and connected between said slide and saidpivotable arms, receptacles in said pivotable arms, telescoping shaftshoused within said receptacles for variable extension outwardlytherefrom and wheel assembly secured to said telescopic shafts, each ofsaid wheel assemblies being provided with individually controlled motormeans.

5. A paving machine having: a carriage and propulsion means therefor;hanger means mounted on said carriage; a pan; rotary vibration producingmeans mounted upon said pan and adapted to rotate about an axisgenerally perpendicular to the line of travel of the machine; avibration filtering system connected with said pan and said carriage,said vibration system comprising a multiplicity of filter units, each ofsaid lter units comprising spring means, means connected with saidspring means and disposed in a vertical attitude in said hanger meansfor generally vertical reciprocation, means supportively connected withsaid vertical reciprocation means for generally horizontal reciprocationwith respect to said vertical reciprocation means and generally parallelto the line of travel of the machine, and means for securing said filterunits to said pan and said carriage; and said carriage comprising ahorizontal main beam, vertical stanchions disposed upwardly from theends of said main beam, adjustable fulcra secured to said main beaminboard of said stanchions, pivotable arms secured to said adjustablefulcra and extending outwardly therefrom in a generally horizontalattitude, tracks formed in said stanchions, a slide confined within eachof said tracks and adapted for vertical adjustment therein, means foradjusting and maintaining the position of said slide within said track,lifting means interposed and connected between said slide and saidpivotable arms, receptacles in said pivotable arms, telescoping shaftshoused within said receptacles for variable extension outwardlytherefrom and wheel assembly secured to said telescopic shafts, each ofsaid wheel assemblies being provided with individually controlled motormeans.

6. A paving machine having: a carriage and propulsion means therefor,said carriage being provided with forwardly and rearwardly projectinghanger means at a plurality of spaced points across said carriage forseating spring means; a pan having a front and rear; rotary vibrationproducing means mounted upon said pan and adapted to rotate about anaxis generally perpendicular to the line of travel of the machine; and avibration filtering system connected with said pan and said carriage;said vibration filtering system comprising a multiplicity of pairs offilter units secured to said hanger means and to said pan, each of saidpairs of filter units comprising a pair of sleeves secured to said pan,one at the front and one at the rear thereof, said sleeves being in ahorizontal attitude with their axes parallel to the line of travel ofthe machine, each of said sleeves having a hole therein, said holehaving a dimension parallel to the direction of travel of the machinewhich is at least equal to the maximum horizontal vibration component ofthe pan under operating conditions, a reciprocable stub-shaft in eachsleeve, a member associated with each sleeve and being disposedreciprocably in a vertical attitude in said hanger means, the memberextending through the elongated slot in said sleeve and being secured tosaid stub shaft, a first spring means, means for retaining said firstspring means on said member above said hanger means, a second springmeans, and means for retaining said second spring means on said memberbelow said hanger means; and said carriage comprising a horizontal mainbeam, vertical stanchions disposed upwardly from the ends of said mainbeam, adjustable fulcra secured to said main beam inboard of saidstanchions, pivotable arms secured to said adjustable fulcra andextending outwardly therefrom in a generally horizontal attitude, tracksformed in said stanchions, a slide confined within each of said tracksand adapted for vertical adjustment therein, means for adjusting andmaintaining the position of said slide within said track, lifting meansinterposed and connected between said slide and said pivotable arms,receptacles in said pivotable arms, telescoping shafts housed withinsaid receptacles for variable extension outwardly therefrom and wheelassembly secured to said telescopic shafts, each of said wheelassemblies being provided with individually controlled motor means.

'7. A paving machine having: a carriage and means for moving saidcarriage along a strip of concrete; a concrete contacting pan mounted onsaid carriage; vibration producing means mounted upon said pan forsetting up vibrations in said pan having generally vertical and hori*zontal components in the direction of travel of said machine; and aplurality of vibration dissipating units interconnecting said pan andsaid carriage at a plurality of spaced points across said carriage, saidvibration dissipating units comprising vertical damping means includingspring means for damping vertical components of vibration between saidpan and said carriage, said dissipating units also includinghorizontally reciprocating means for generally maintaining thehorizontal position of said pan with respect to said carriage as saidmachine moves along such strip while permitting horizontal movement ofsaid pan parallel to said horizontal components over a distance which isas great as the horizontal component of vibration of said pan whenvibrating in contact with such a strip of concrete.

References Cited by the Examiner UNITED 1/1925 1/1934 4/1936 4/19365/1936 lll/1937 3/1938 5/1939 9/1940 12/1940 12/1957 l/1959 11/19611/1962 STATES PATENTS Ord 94--48 Gordon 914-48 Clitford 94-48 Hertvvig94-48 McCrery 94--48 Baily 94--48 Baily 94-48 Schieferstein 94--48Venable 94--48 Baily 94-48 Northcote 2SC-414.5

Westberg ZBO- 43.23

Nave 94-48 Apel 94-45 2O JACOB L. NACKENOFF, Primary Examiner.

WILLIAM l. MUSHAKE, Examiner.

2. A PAVING MACHINE HAVING: A CARRIAGE AND PROPULSION MEANS THEREFOR;HANGER MEANS MOUNTED ON SAID CARRIAGE; A PAN; ROTARY VIBRATION PRODUCINGMEANS MOUNTED UPON SAID PAN AND ADAPTED TO ROTATE ABOUT AN AXISGENERALLY PERPENDICULAR TO THE LINE OF TRAVEL OF THE MACHINE; AND AVIBRATION FILTERING SYSTEM CONNECTED WITH SAID PAN AND SAID CARRIAGE,SAID VIBRATION FILTERING SYSTEM COMPRISING A MULTIPLICITY OF IDENTICALFILTER UNITS AT SPACED INTERVALS ACROSS SAID CARRIAGE, EACH OF SAIDFILTER UNITS COMPRISING SPRING MEANS, GENERALLY VERTICALLY DISPOSEDMEANS CONNECTED WITH SAID SPRING MEANS AND SAID HANGER MEANS FORGENERALLY VERTICAL RECIPROCATION, A FIRST GENERALLY HORIZONTAL MEMBERSECURED TO SAID GENERALLY VERTICALLY DISPOSED MEANS, AND A SECONDGENERALLY HORIZONTAL MEMBER CONNECTED IN SUPPORTIVE ENGAGEMENT WITH SAIDFIRST GENNERALLY HORIZONTALLY MEMBER FOR HORIZONTAL RECIPROCATION WITHRESPECT THERETO AND GENERALLY PARALLEL TO THE LINE OF TRAVEL OF THEMACHINE, SAID SECOND GENERALLY HORIZONTAL MEMBER BEING SECURED TO SAIDPAN.